133, 141. Retina, 247. Retorts, 395. Reversing gear, 62; Allan, 65; Gooch, 65; radial, 66. Rocking bar mechanism for watches, 415. Gooch reversing gear, 65. Governors, speed, 67; of motor car, 110; railway, 187; vacuum, 189, _190_, _191_. Vacuum chamber of aneroid barometer, _330_. Valve, piston, 67; safety, 32; of internal-combustion engines. The.